Cylindrical drum mill with plurality of pivotally mounted hammers on inner periphery



June 25, 1957 k N. A. PIERSON 2,797,051

cyuunmcm. DRUM MILL WITHT-PLURALITY 0F PIVOTALLY MOUNTED HAMMERS-QN-h-INNER PERIPHERY Fi l e'd Feb. 18, .1955

IN V EN TOR. NA Pz'e/"so/z A r TORNEX CYLINDRECAL DRUM MELT. WITHPLURALTTY F PIVOTALLY MQUNTED HAl /IMERS 0N DJNER PERKPHERY Norman A.Pierson, Norman, Okla, assignor to Naturizer Co, Norman, Okla, acorporation of Uitlahoma Application February 18, 1955, Serial No.489,131 3 filairns. (Cl. 241-176) This invention relates generally toimprovements in grinding apparatus, and more particularly, but not byway of limitation, to an improved pulverizer for reducing the aggregatesize of municipal refuse.

The present invention contemplates a novel pulverizer utilizing acylindrical housing having a plurality of hammer elements pivotallysecured to the inner periphery of the housing. The housing is rotatedaround its longitudinal axis while the articles to be pulverized arepassed lengthwise through the housing. During rotation of the housing,the hammer elements are pivoted to strike the articles by centripetalforce. Although not limited thereto, my novel pulverizer is particularlyadapted for use in pulverizing municipal refuse. Municipal refusenormally contains hard articles such as tin cans, tree limbs and rockswhich cannot be pulverized by the present day apparatuses, such ashammer mills. The present pulverizer beats, tears and masticates sucharticles to small aggregate size for use in composting operations.

An important object of this invention is to pulverize substantially allarticles normally contained in municipal refuse.

Another object of this invention is to provide a novel pulverizer whichprovides a combination beating and masticating action on articlespassing therethrough.

Another object of this invention is to provide a novel pulverizerutilizing pivotal hammers operated by centripetal force for reducing theaggregate size of articles passing therethrough.

A further object of this invention is to provide a novel pulverizer formunicipal refuse which provides an efiicient aerating of the refuse, aswell as pulverization.

Another object of this invention is to facilitate the composting ofmunicipal refuse.

A still further object of this invention is to provide a simplyconstructed pulverizer which may be economically manufactured.

Other objects and advantages of the invention will be evident from thefollowing detailed description, when read in conjunction with theaccompanying drawings which illustrate my invention.

In the drawings:

Figure 1 is a plan view of my novel pulverizer.

Figure 2 is a sectional view taken along lines 22 of Figure 1.

Figure 3 is a typical elevational view of one of the hammer elements andits attaching bracket.

Figure 4 is another typical elevational view of a hammer element asviewed 90 from Figure 3.

Referring to the drawings in detail, and particularly Figures 1 and 2,reference character 6 generally designates my novel pulverizer mountedon a base 8. The base 8 may be constructed in any suitable manner tosupport a pair of idler rollers 10, driving rollers 12 and power unit14.

The idler rollers are mounted in aligned relation on the opposite endsof an idler shaft 16. A pair of bearing members 18 are secured in spacedand aligned 1;; Pat

relation on the base 8 to receive the shaft 16 and rotatably support therollers 10 in fixed vertical positions, as will be more fullyhereinafter set forth. The driving rollers 12 are mounted on theopposite ends of a shaft 20 in spaced, but aligned, relation to theidler rollers 10. The shafts 16 and 20 are supported in parallelrelation. A pair of bearing members 22 are secured in spaced relation onthe base 8 to rotatably support the shaft 20 and driving rollers 12.

A suitable gear box 24 is connected to the central portion of the shaft20 to transmit power from the engine 14 and drive shaft 26 to the shaft20. The base 8 is suitably formed to support the gear box 24 and engineor power unit 14.

An elongated cylindrical housing 31) extends between and in parallelrelation to the shafts 16 and 20, and rests on the rollers 14 and 12.The housing 30 is hollow and has an inlet end 32 and an outlet ordischarge end 34. A curved spout 36, having an inlet aperture 38 ofsmaller diameter than the inner diameter of the housing 30, is rigidlysecured around the inlet end 32 in any suitable manner, such as bywelding. An annular shaped baffle plate 40 is secured around the outletend 34 of the housing 30. The baffle plate 40 has an inner diameterslightly smaller than the inner diameter of the inlet spout aperture 38for purposes as will be hereinafter set forth.

The housing 30 is preferably tilted downward towards the discharge end34 to move the material (not shown) being pulverized through the housingby gravity. Therefore, the shafts 16 and 2d are also tilted or slantedin the same direction. Any suitable stopping roller (not shown) may beextended from the base 8 to the lower discharge end 34 to preventlengthwise slippage of the housing 30 on the rollers 10 and 12.

A plurality of hammer elements 44 are pivotally secured to the innerperiphery of the housing 30 to reduce the aggregate size of the refuseor other material being pulverized. Each hammer element 44 (see Figures3 and 4) comprises an elongated body portion 46 having irregular orjagged teeth 48 formed in the small sides thereof over substantiallyone-half the length of the body. The outerend 49 of each hammer body 46is rounded and pivotally secured in a bracket 51 extending inwardly fromthe inner periphery of the housing 30. Each bracket 50 is formed in twosections rigidly secured to the housing 30 in spaced relation to receivethe hammer 44 therebetween. A bolt 52 extends through each bracket 50and the respective hammer body 46 to pivotally secure the hammers 44 inthe housing 30 whereby the hammers may pivot transversely in the housing30.

As shown in Figure 2, the hammers 44 are secured in four rows 60, 70,and along the length of the housing 30. Each of the rows 60, 70, 80 and90 is arranged in a spiral around the inner periphery of the housing 30as illustrated by the dotted lines for rows 60 and 10 in Figure 1. Inorder to clarify the illustration, rows '70 and 81) are not shown inFigure 1. Also, the hammers 44 in each row are spaced along the lengthof the housing 30 from the adjacent hammers in adjacent rows. Forexample, the hammer 44 in row 70 nearest the housing inlet 32 (the firsthammer) may be spaced two inches along the length of the ,housing 30from the first hammer in row 60; the first hammer 44 in row 80 may bespaced in the same manner from the first hammer in row 70, etc.

It will thus be seen that when progressing from the inlet end 32 towardthe outlet end 34 of the housing 30, each hammer 44 in each row isspaced both longitudinally and circumferentially from the adjacenthammers 44 in the adjacent rows. It is also desirable that each hammer44 be secured to the housing 30 over ninety degrees from the adjacenthammer 44 in the adjacent rows. As will be observed in Figure 2, thehammer 44 in row 60 nearest the end 32 of the housing 30 is spaced morethan ninety degrees from the first hammer 44 in row 70 and so on aroundthe inner periphery of the housing. This circumferential spacing featurehas been magnified inFigure 2 for purposes of clarifying theillustration. In an actual installation, the circumferential spacing maybe only slightly over ninety degrees, such as ninety-one degrees. Itshould also be noted that although it appears in Figure 2 that the firsthammer 44 in row 90 is lessthan ninety degrees from row 60, whenreferring to Figure 1 it will be apparent that the first hammer 44 inrow 90 is actu: ally closer to the second hammer in row 60, and thespacing therebetween is in excess of ninety degrees. Therefore, thecircumferential spacing described above holds true for all of the rowsof hammers.

Operation In utilizing the pulverizer 6, the power unit 14 is firstplaced in operation to rotate the driving rollers 12 through the shaft26, gear box 24 and shaft 20. The rollers 12 frictionally engage theouter surface of the housing 30 to rotate the housing around itslongitudinal axis. The idler rollers assist in supporting the housing30, and are rotated by the housing simultaneously with the rotation ofthe driving rollers 12.

Refuse or other material tobe pulverized is fed into the housing throughthe inlet chute aperture 38, and progresses by gravity through thehousing 30 and out of the baffle plate at the outlet end 34 of thehousing. The refuse may be fed into the housing 30 by any suitablemeans, and the chute 36 tends to prevent a spilling of the refuse out ofthe inlet end 32. The baffle plate 40 retards the discharge of refuseand assures a suflicient level of refuse in the housing 30 for anefficient action of the hammer elements 44 as will now be described.

The housing 30 may be rotated in either direction but for the purposesof illustration, it will be assumed that the housing 30 is rotatedclockwise when viewed at the inlet as shown in Figure 2. As each hammer44 reaches the crown of the housing 30, or the uppermost position of thehammer, it hangs downward toward the center of the housing 30 asillustrated by the first hammer in row 60. During continued rotation ofthe housing, the hammer 44 pivots counter-clockwise to rest on therefuse or inner surface of the housing in the position illustrated bythe first hammers in rows 70 and 80. However, as the bracket of therespective'hammer 44 moves upward above the center line of the housing30, the hammer 44 pivots clockwise with substantial force into therefuse into the position shown by the first hammer in row 90 in Figure2. V

The spiral arrangement of the hammers 44, along with the circumferentialspacing of the hammers in adjacent rows, results in only one hammerstriking the refuse at one time. Therefore, the shock on the housing 30will be retained at a minimum, to obtain the maximum striking force foreach hammer.

The force at which each hammer 44 strikes the refuse is dependent firstupon the weight of the hammer, and secondly upon the speed of rotationof the housing 30. As each hammer 44 begins to pivot and fall, itsrespective bracket 50, being moved upward, forces the outer end 49 inthe opposite direction to provide an added rotation and centripetalforce to the toothed portion of the hammer. Each hammer 44 strikes therefuse with substantial force to provide a beating or pulverization ofthe refuse. It will be observed in Figure 2 that each hammer 44 is of alength to overlap the adjacenthammers 44 in adjacent rows-note the firsthammers 44 in rows 80 and 90. Therefore, the refuse will also bemasticated and ground between the falling hammer and the adjacenthammers, as well as between the falling hammer and the inner peripheryof the housing 30. It will also be observed that the refuse will beturned by the rotation of the housing 30 and action of the hammers 44 toprovide a complete aeration and homogeneous mixing of the refuse.

In utilizing the pulverizer 6 for grinding or pulverizing refuse, thehammers 44 will efficiently grind up hard articles such as tin cans,tree limbs, wooden boxes, bones, etc., as well as the usual softportions of the refuse, such as paper, cardboard, vegetable matter andcooking scraps. The size of the pulverizer will, of course, determinethe size of articles which may be pulverized. However, substantially anyarticle which is normally found in municipal refuse and which may bepassed through the housing 30 will be beat, torn and masticated to asmall aggregate by the hammers 44.

The capacity of the pulverizer 6 may be varied by changing the tilt ofthe housing 30. When the height of the inlet end 32 is increasedrelative to the outlet end 34, the refuse will move through the housingat a faster rate and the capacity will be increased. However, theaggregate size of the refuse discharging through baffle 40 will beincreased, since the refuse will be subjected to a shorter period ofaction by the hammers 44. Contra, the capacity is decreased by levelingthe housing 30, but the aggregate size of the refuse will be decreased.The aggregate size of the refuse being discharged may be increased bydecreasing the spacing between the hammers 44 along the length of thehousing 30, and vice versa. Also, the housing 30, having a solid wall,prevents the loss of moisture from the refuse. Water may be applied tothe refuse at the inlet end 32, and the thorough mixing of the refuse,along with the retention of moisture in the housing 30 and con stantflow of refuse through the housing, facilitates the obtaining of a smallaggregate refuse having a constant moisture content.

From the foregoing, it is apparent that the present invention provides anovel pulverizer which will pul' verize substantially all articlesnormally contained in municipal refuse. The hammer elements are pivotedby centripetal force and provide a combination beating and masticatingaction on articles passing through the pulverizer. When used forpulverizing municipal refuse, the present invention provides anefficient aerating of the refuse and facilitates the retention of aconstant moisture content for the refuse.

Changes may be made in the combination and arrangement of parts asheretofore set forth in the specification and shown in the drawings, itbeing understood that any modification in the precise embodiment of theinvention may be made within the scope of the following claims withoutdeparting from the spirit of the invention.

I claim:

1. A pulverizer, comprising a hollow cylindrical housing, said housingbeing rotatable around its longitudinal axis, a row of elongated hammerspivotally secured along the inner periphery of said housing, a secondrow of elongated hammers pivotally secured along the inner periphery ofsaid housing, said rows being circumferentially spaced more than ninetydegrees and spiral in configuration, and each of said hammers beingsecured to pivot transversely in said housing upon rotation of saidhousing.

2. A pulverizer, comprising a hollow cylindrical housing, said housingbeing rotatable around its longitudinal axis, a row of elongated hammerspivotally secured along the inner periphery of said housing, a secondrow of elongated hammers pivotally secured along'the inner periphery ofsaid housing, said rows being circumferentially spaced more than ninetydegrees, and each of said hammers being secured to pivot transversely insaid housing upon rotation of said housing.

' 3. A pulverizer, comprising a hollow cylindrical housing, said housingbeing rotatable around its longitudinal axis, a row of elongated hammerspivotally secured along the inner periphery of said housing, a secondrow of elongated hammers pivotally secured along the inner periphery ofsaid housing, said rows being spiral shaped and circumferentially spacedmore than ninety degrees, each hammer in said first row being spacedalong the length of said housing from the adjacent hammers in saidsecond row, and each of said hammers also being of a length to overlapthe adjacent hammer in the opposite row when said hammers are pivotedtoward one another.

References Cited in the file of this patent UNITED STATES PATENTS

